DTC Advanced Diagnostics: P011A
DTC P011A:Engine Coolant Temperature (ECT) Sensor 1 Circuit Range/Performance Problem

General Description


The powertrain control module (PCM) monitors engine coolant temperature (ECT) sensor 1 for electrical malfunctions. In order to provide diagnosis the measured engine coolant temperature is monitored against expected engine coolant temperature at engine start. The expected engine coolant temperature is a modeled temperature which represents the lowest possible heating up of engine coolant temperature. The measured engine coolant temperature is always higher than expected temperature value in case of valid sensor. If the difference between the ECT sensor 1 output temperature and mean value of all temperature sensors at cold start is more than a specified value for a specified time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence
None
Duration
90 seconds or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
Engine off time
6 hours
–
State of the engine
Running

Malfunction Threshold
The difference between the ECT sensor 1 output temperature and mean value of all temperature sensors at cold start is more than 44 °F (24 °C) for at least 90 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
ECT sensor 1 failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Start the engine and drive the vehicle for at least 2 minutes.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.